6533b7d9fe1ef96bd126cc16

RESEARCH PRODUCT

Alterations of Continuous MEG Measures during Mental Activities

Michael GrözingerJürgen FellHans-jochen HeinzeJoachim RöschkeHermann Hinrichs

subject

AdultMaleCorrelation dimensionmedicine.medical_specialtyEntropyFixation OcularLyapunov exponentAudiologyLateralization of brain functionDevelopmental psychologysymbols.namesakeCognitionMental ProcessesmedicineHumansEntropy (information theory)Biological PsychiatryBrainMagnetoencephalographySpectral bandsPsychiatry and Mental healthNeuropsychology and Physiological PsychologyAmplitudeNonlinear DynamicssymbolsFemaleSleep StagesSpectral edge frequencyPsychologyAlgorithmsMental image

description

In a pilot study, we investigated the topography of 11 continuous MEG measures for the eyes-opened and eyes-closed condition together with three simple mental tasks (mental arithmetic, visual imagery, word generation). One-minute recordings for each condition from 16 right-handed subjects were analyzed. The electrophysiological measures consisted of 6 spectral band measures together with spectral edge frequency and spectral entropy, plus the time-domain-based entropy of amplitudes (ENA) and the nonlinear measures correlation dimension D2 and Lyapunov exponent L1. In summary, our results indicate a pronounced task-dependent difference between the anterior and the posterior region, but no lateralization effects. Although the nonlinear measures ranged in the middle field with respect to the number of significant contrasts, they were the only ones to be partially successful in discriminating the mental tasks from each other. The most efficient measure turned out to be the ENA. Under mental activation the ENA was larger than in both no task conditions (eyes opened and eyes closed). This finding reflects lower variations of the maximum amplitude during performance of mental tasks than during no task states.

yearjournalcountryeditionlanguage
2000-08-15Neuropsychobiology
https://doi.org/10.1159/000026679